One of them is Loeb himself; the other three have backgrounds that reveal where Loeb thinks Yahoo should go.

Harry Wilson is the CEO of Maeva, a corporate restructuring and turnaround firm; Michael Wolf is CEO of media consulting company Activate; and Jeffrey Zucker is the former CEO of NBC Universal.

Third Point, which owns a 5.56% stake in Yahoo, filed its paperwork one week to the day after Yahoo revealed that four of its longtime Yahoo members, including chairman Roy Bostock, are stepping down. Yahoo said it has already picked two board members to replace them and would search for more.

Critics had called for the board directors' heads as Yahoo's (YHOO, Fortune 500) struggles continued. The company gave up on search in 2009, and it's losing ground in display advertising to new entrants to the market such as Google (GOOG, Fortune 500) and Facebook.

Third Point said in its filing that it was "pleased" with the four exits, but it remains concerned about the selection of new directors.

"Installing the hand-picked choices of the current board does nothing to allay investor fears that Yahoo is poised to repeat the errors of its past," Third Point wrote in the filing.

Loeb has frequently spoken out against Yahoo's board, particularly company Yahoo co-founder Jerry Yang -- who resigned his board post and all other positions at the company last month.

Though he says he's cheered by the recent changes, Loeb is clearly spoiling for a fight. Bess Levin at Dealbreaker notes that this is something of a Valentine's Day tradition for him: Salton Inc., Star Gas Partners and AEP Industries received similar letters on February 14 of years past.

Another activist shareholder, the legendary Carl Icahn, launched his own battle with Yahoo in 2008. Icahn wanted to oust Yang, the Yahoo co-founder, after the company snubbed a $47 billion buyout bid from Microsoft (MSFT, Fortune 500).

Icahn snapped up Yahoo shares by the millions, and he said in May 2008 that he would launch a proxy fight over the Microsoft deal. The scuffle ended in July of that year, when Icahn joined Yahoo's board. He left the post in October 2009.